cylonlover writes: Following on from a successful maiden flight under battery power in 2010, AeroVironment’s high altitude, long endurance (HALE) Global Observer unmanned aircraft has now taken to the skies using hydrogen-fueled propulsion. The aircraft reached an altitude of 5,000 feet during the four hour flight on January 11 at Edwards Air Force Base (EAFB) in California. Both the endurance and the altitude of the system will be expanded in further test flights in order to achieve the planned operational altitude of 55,000 to 65,000 feet.